This invention relates to abrasive bodies.
Cubic boron nitride abrasive compacts are well known in the art and are used in the cutting, grinding and otherwise abrading of various workpieces, particularly iron-containing workpieces. In use, they may be mounted directly on to a tool or bonded to a cemented carbide backing prior to mounting on to the tool.
Cubic boron nitride compacts consist essentially of a mass of cubic boron nitride particles present in an amount of at least 70 percent, preferably 80 to 90 percent, by volume of the compact bonded into a hard conglomerate. The compacts are polycrystalline masses and can replace single large crystals.
Cubic boron nitride compacts invariably contain a second bonding phase which may contain a catalyst (also known as a solvent) for cubic boron nitride growth. Examples of suitable catalysts are aluminium or an alloy of aluminium with nickel, cobalt, iron, manganese or chromium. When the bonding matrix contains a catalyst, a certain amount of intergrowth between the cubic boron nitride particles occurs during compact manufacture.
Cubic boron nitride compacts are made under conditions of temperature and pressure at which the cubic boron nitride particles are crystallographically stable.
U.S. Pat. No. 3,982,911 describes another type of composite abrasive body comprising a layer of alloy-bonded cubic boron nitride crystals directly bonded to a metal substrate. The abrasive body is manufactured under relatively low pressure conditions which will not result in intergrowth occurring between the cubic boron nitride particles.